While finishing up my right elevator I noticed this gap between the inboard rib and the trailing edge. I am not talking about the fact that it is open (since it is supposed to be) but rather the bend in the metal skin between the aft end of the rib and the trailing edge. When relaxed it bends outward, when pressed with my finger in bends inward. When I release the metal it make the distinctive pop as it bends back outward.

I am thinking I will place some pro-seal on the last quarter inch of rib (between the rib and skin) to hold the metal skin inward. Any other thoughts on the topic would be greatly appreciated.

Not completely sure how this manifested itself (I am thinking it is how the proseal on the foam rib dried to the skin), but figure it is more of an annoyance than a structural issue as long as it doesn't fatigue over time from movement back and forth.

Are you sure the trailing edge wedge is installed in the correct direction?

In the photos it looks as if it is installed backwards...

Quote:

Your wedge is backwards.

The thin side should be aft and the thick side fwd.

Not on the 14 .. the depicted installation direction is correct.

Had a long discussion with the mothership about this during my factory tour. The prototype 14 had an undesirable mushy stick feel in some conditions that was resolved by this trailing edge design departure from previous RVs.

Concur, your wedge is installed correctly. This is where I like having the plans in PDF and an iPad. You can zoom in areas and get good detail if necessary. The drawings clearly show the thin side of the edge inward.

While finishing up my right elevator I noticed this gap between the inboard rib and the trailing edge. I am not talking about the fact that it is open (since it is supposed to be) but rather the bend in the metal skin between the aft end of the rib and the trailing edge. When relaxed it bends outward, when pressed with my finger in bends inward. When I release the metal it make the distinctive pop as it bends back outward.

I am thinking I will place some pro-seal on the last quarter inch of rib (between the rib and skin) to hold the metal skin inward. Any other thoughts on the topic would be greatly appreciated.

Not completely sure how this manifested itself (I am thinking it is how the proseal on the foam rib dried to the skin), but figure it is more of an annoyance than a structural issue as long as it doesn't fatigue over time from movement back and forth.

Pictures didn't load, will post them tonight on a different computer

Is that one of the foam ribs visible inside?

If so, it doesn't look like it is entirely bonded to the skin and it looks like it is a bit too tall, causing the skins to be spread apart. The aft end of the foam rib should be about the same height as the fwd edge of the T.E. wedge so that there is a neutral transition from the on onto the other.

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I didn't notice it while looking at the Elevator, but in the picture it does appear to be de-bonded. I will take a look tonight, but the Trailing edge is nice and straight with no bulging at the transition between the foam rib and the trailing edge filler. It almost seems as if the entire trailing edge is about 1/8 to 1/4" too low, but it is only manifesting itself at the inboard rib with the bulge as seen in the picture. That is why I am a bit perplexed. The real question is do I simply accept it as a flaw and move on, or could it have greater implications that I am not tracking. For now, I am thinking pro-seal as best possible and move on.

Valid point to consider though. If the foam ribs were too thick then it would shorten the distance of the skin from the rear spar to the trailing edge. I had trimmed the foam ribs exactly to the template, but never checked the trailing edge thickness against the trailing edge filler piece. May be worth adding this step for anyone approaching this portion of the build as that is likely the cause of the skin bulge that is present on the inboard rib.

Any aero or mechanical engineers have thoughts on long term effect of this in regards to performance or structural fatigue life.

I looked last night and the foam rib in the picture is slightly de-bonded in the middle. Also, the rib is the correct thickness as the two photos I posted earlier were simply at a bad angle and made the rib appear thicker at the trailing edge. Of note, their is about a quarter inch gap from the aft edge of the foam rib to the leading edge of the trailing edge wedge (I know, tough to follow that sentence) which accounts for variation in thickness from the foam rib to the trailing edge piece.

I will inject some pro-seal near the de-bonded foam rib along with between the metal rib / skin, clamp, and move on. No real performance or structural issues that I can imagine moving forward. Thanks for the input

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